When should passengers on delayed flights be compensated?

The European Parliament will vote on a package of measures on Wednesday to clarify passengers' rights when flying.

The bill includes the right for passengers to disembark planes stuck on the tarmac after two hours, and compensation if their short haul flight is delayed by three hours or more.

David Henderson from the Association of European Airlines told BBC World there needed to be clarification of what constituted "extraordinary circumstances" - when an airline is not deemed liable for disruption.